Chimpanzees recognise their friends after decades

03/01/2024 in Edinburgh Zoo

Here at Edinburgh Zoo we are home to 15 chimpanzees, all of which live in one of the world's most innovative and interactive chimpanzee enclosures, Budongo Trail.

Within this habitat is the Budongo Research Unit (BRU), a cutting-edge research centre in partnership with the University of St Andrews, which aims to advance scientific knowledge on chimpanzee cognition and behaviour.

Recently, a former BRU researcher and visiting PhD student from the University of St Andrews, Laura Lewis, published a paper in renowned scientific journal PNAS which found that chimps can recognise their companions even after decades apart.

While human social memory lasts decades and can track relationships, much less is known about nonhuman apes’ long-term memory.

By using special eye-tracking technology during voluntary interactive sessions, Laura showed our chimps pairs of photos of other chimpanzees on a screen. The eye tracker recorded where on the screen they looked, and revealed those who chose to take part spent more time looking at photos of old groupmates (who had either moved to another zoo or passed away), compared to photos of chimpanzees they had never met.

Alongside data collected from Planckendael Zoo in Belgium (bonobos) and the Kumamoto Sanctuary in Japan (chimpanzees and bonobos), Laura's research has shown that just like humans, bonobos and chimpanzees have long-term social memories and can remember their friends and family for many years after they last saw them!

Callum Gibson, Budongo team leader at Edinburgh Zoo said, “Our chimpanzee troop voluntarily spend time in the Budongo Research Unit, which can be found on the ground floor of our chimp habitat. Alongside our partners from the University of St Andrews, the chimps undertake cognitive puzzles and games as they please.

“Our wildlife conservation charity and the university have a long-standing partnership, working closely together to better understand the cognitive abilities of some of our primates. Laura's recent findings not only provide us with incredibly interesting information and help us to better understand this species, but also helps identify the important role zoos can play in improving our knowledge and understanding of these incredible species.”

As well as the research within BRU, our troop are part of the endangered species breeding programme for western chimps. Our wildlife conservation charity also supports chimpanzees in the Budongo Forest in Uganda through our work with the Budongo Conservation Field Station (BCFS). The BCFS combines cutting-edge research with practical action on the ground to study and protect a community of nearly 700 wild chimpanzees. The project has looked to establish the Budongo Forest Reserve as a model for tropical rainforest management and is overseen by a predominantly Ugandan team.

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